The invention relates to a system for the displacement of a neck rest in response to the displacement of a vehicle seat in an automobile.
A system for the automatic displacement of a neck rest has become known from DE 198 30 753. The system concerns an automatic neck rest retraction while the vehicle seat is tilted to the front. The neck rest is biased by a spring to a predetermined height position and is retracted by means of a single pulling element while the seat is tilted.
A longitudinally adjustable vehicle seat having a height-displaceable neck rest has become known from DE 195 13 705 A1. The adjustment in height of the neck rest is made dependent on the seat""s longitudinal adjustment position to such an extent that the neck rest takes its lowest position when the seat is in its foremost position and takes its highest position when the seat is in its rearmost position. A structural part which is height-displaceably mounted in the seat back and is connected to the bars of the neck rest is actuated via a reversed pulling rope which is connected to the lower end adjacent to an end of the top rail of the pair of seat rails. DE 37 18 126 A1 has made known a combined seat length and seat height displacing system for vehicle seats in which, upon activation of the seat height vertical displacing system, an activation of the horizontal seat length displacing system can be initiated in a sense that the distance between the heel point and the hip point of a person using the vehicle seat is maintained in accordance with a resultant overall movement of the vehicle seat. This activation of the displacing system may be coupled to an engine-driven neck rest displacing system. An engine-driven neck rest displacing system has also become known from DE 196 31 454 A1.
In some cases, it is desirable to effect the automatic coupling between the longitudinal seat displacing system and the neck rest position in a mechanical manner, i.e. only via a limited displacement path of the seat.
Therefore, it is an object of the invention to provide a system for the displacement of a neck rest in response to the displacement of a vehicle seat wherein a coupling of the two parts is intended to be performed only via a limited path of the seat. Moreover, the neck rest is intended to be locked with no regard to the position of the seat.
The inventive system provides for a rope defining a loop which is guided about two idle rollers which are fixedly connected to the seat. One idle roller fixedly connected to the seat back is above a first structural part to which the neck rest is fixed, and is height-displaceably mounted to a second structural part fixedly connected to the seat back. The second roller is in the lower frame of the seat which is displaceable along a rail assembly which is fixedly connected to the vehicle and vehicle bottom. It is understood that more idle rollers may be provided for guiding the rope from the seat back into the seat frame. The rope has connected thereto a coupling part, e.g. a so-called barrel, as is common for pulling cables or Bowden cables. Furthermore, a coupling element is provided which is movably supported in the seat and is selectively engageable with or disengageable from the first coupling part. An actuating means for the coupling element on the seat is actuated by a coupling part fixedly connected to the vehicle. Such actuation is performed in response to the position of the vehicle seat. In a forward position or the foremost position of the seat, the coupling part fixedly connected to the vehicle is in engagement with the actuating means which, in turn, positively grips the coupling element. Now, if the seat is displaced to the rear from this position the first coupling part is retained and a relative movement takes place between the coupling part and the idle rollers, which causes the neck rest to be extracted.
The engagement between the actuating means and the coupling part fixedly connected to the vehicle is only effected along a limited path and the neck rest will be displaced only as long as this engagement persists. Subsequently, the second coupling part gets out of engagement with the actuating means, which also terminates the engagement of the coupling element with the first coupling part. Now, the seat may be displaced more to the rear with no need to actuate the neck rest once more.
Finally, the inventive system provides for locking means which lock the first coupling part when the coupling element is in disengagement with the first coupling part. In this way, a provision is made that if the seat continues to be displaced to a rear position the neck rest remains in the position it has taken and can neither be extracted nor retracted.
Thus, the invention provides that the displacement of the neck rest be automatically coupled to the first displacement path of a seat to the rear from a forward position. For example, a coupling between the displacing system of the two parts is performed only along a path of from 80 to 100 mm whereas the neck rest invariably maintains its position for the rest of the displacement path. It is understood that if there is a displacement to the forward position from a rearward one the second coupling part will again get into engagement with the actuating means if these have arrived at the second coupling part in order to cause the coupling element to be coupled to the rope again until the seat is displaced to the front or foremost positions. At this point, the locked position of the neck rest is always ensured.
Various constructional versions are possible in designing the coupling element and the actuating means. One aspect of the invention comprises an elongated guidance fixedly connected to the seat and having a first and a second guiding portion, a locking element which is guided along a second elongated guidance fixedly connected to the seat and having a first and a second guiding portion with the first guiding portion of first and second guidance each extending approximately parallel, and the second guiding portion of first and second guidance are preferably angulated with respect to the first guiding portion towards the same side wherein the coupling element is linked to the locking element and guided along a third elongated guidance fixedly secured to the seat, the second guidance extending approximately parallel to the first guiding portion of the first and the second guidance, with the coupling element engaging the second coupling part if the seat is in a forward position and the locking element is within the area of the first guiding portion of the second guidance while the second coupling part is in disengagement with the locking element if it is in the second guiding portion of the second guidance, the coupling element has a coupling slot such that the first coupling part engages an inner end portion of the coupling slot if the first coupling part is in the first guiding portion of the first guiding whereby through a movement of the coupling element in both directions the first coupling part is also moved, however, is moved out of the inner end portion if the first coupling part is in the second guiding portion of the first guidance, and the coupling element has a stop surface which restricts an engagement recess of the locking element, which recess becomes free when the locking element is pivoted upon an engagement of the locking element with the second guiding portion of the second guidance. In this aspect of the invention, the first guidance provides for the first coupling part, e.g. the barrel fixed to the rope, to be moved out of the coupling slot or to be relieved of its positive engagement with the coupling element when the first coupling part gets into the second guiding portion and is pivoted accordingly. Then, another relative movement between the coupling element and the first coupling part will smoothly be possible. A displacement of the neck rest will no longer occur. However, as the locking element is no longer intended to be carried along, if possible, there is also a uncoupling action between the second coupling part and the locking element so that the coupling part completely gets out of engagement with the actuating means. In the embodiment described last, this is done by pivoting the locking element which then releases the coupling part. The locking element is pivoted by the second guidance by the fact that a coupling portion of the locking element gets into the second guiding portion of the second guidance. At the end of the second guiding portion of the first guidance, the first coupling part is held in such a way that pulling the rope in both directions does not cause the coupling part to be displaced in the first guidance or the second guiding portion of the first guidance.